1. Field of the Invention
The present invention relates to a method and an apparatus for controlling a recorder, including a video camera recorder which can shoot landscapes, persons, and the like, and record them as moving image information, and an editing recorder which edits this moving image information and so on.
2. Description of the Related Art
Conventionally, video camera recorders such as a handy video camera have been used to shoot surrounding environment and retain it for record. While various types of tape recorders used to be used as recording media, optical recording media such as CD and DVD have been increasingly adopted for the recording media recently as described in Japanese Patent Application Laid-Open No. 2001-223929.
Video camera recorders for recording moving image information on an optical recording medium when necessary include such components as: an image conversion unit for receiving ambient tight and converting it into moving image information; a recording mechanism for recording this moving image information on an optical recording medium; an optical mechanism for performing zooming and a focus control by using a lens and the like; and a battery unit for functioning as a power supply.
Now, with the prevalence of TV sets that can deliver HDTV images, video camera recorders for business use have also been requiring high-definition shooting of moving images recently. In consequence, the video camera recorders are growing in the amount of moving image information per shooting time. To meet this demand, commercialization has started of so-called next-generation DVDs which are capable of recording a large volume of moving image information. For example, the Blu-ray Disc (BD) standard makes it possible to record moving images up to 25 GB on a single recording layer, with the objective lens of the foregoing recording mechanism set to 0.85 in numerical aperture.
Since the video camera recorders are required to record captured moving image information on their optical recording medium in real time, the compression format (recording rate) of the moving image information is of high importance. For example, a moving image compression format that requires a recording rate of 100 Mbps can record high-definition moving images since the rate of transfer to the optical recording medium is high. A moving image compression format with a recording rate of 35 Mbps can only record low-definition moving images since the rate of transfer to the optical recording medium is low. In the meantime, the moving image compression format requiring the recording rate of 100 Mbps can only record moving images on an optical recording medium for a short time since the amount of information to be transferred is high. The moving image compression format with the recording rate of 35 Mbps can record moving images on an optical recording medium for long hours since the amount of information to be transferred is low.
Moving image information that has been captured by a video camera recorder and recorded on an optical recording medium is edited by an editing recorder, installed in a studio or the like, and recorded on an optical recording medium. This editing recorder is also required to edit moving image information of high definition at high speed. The recording rate is thus essential as is the case with the foregoing.
For recorders in business use, like ones intended for producing programs in TV stations, it is essential to provide both high-definition images and sufficient recording time in a consistent fashion. In particular, video camera recorders must by all means avoid the situation of being completely unavailable for shooting due to an insufficient capacity of their optical recording medium. Optical recording media of rewritable type are adopted for this reason.
These rewritable optical recording media, however, have had the problem that the recording rate is harder to increase since the recording marks are formed by causing a phase change in their information recording layer by means of laser-based heating and cooling. In other words, despite the video camera recorders being for business use, the necessity of avoiding the unrecordable situation has set a certain limit in increasing the image definition.